JSON Validator

Check whether JSON is valid and see where it first fails. It runs in your browser.

How to use it

1. Paste your JSON.
2. Read “Valid JSON”, or the line, column and message of the first error.
3. Fix the problem and check again.

Example

{"a":1,} fails at line 1, column 8 with “Expected double-quoted property name”: the parser reached the trailing comma and expected another key. {"a":1} is valid.

Common causes

• A trailing comma after the last item.
• Single quotes, or keys without quotes.
• Comments, which JSON does not allow.
• undefined, NaN or Infinity.
• Unescaped quotes or raw line breaks inside a string.

Good to know

A parser stops at the first problem, so fix one error and check again. The real mistake is often on the line before the one reported. Valid only means the syntax is right; the tool cannot tell whether the fields match what an API expects. A single value such as 42 or "hello" is valid JSON too.

See how to validate JSON, or tidy a valid document with the JSON Formatter.

FAQs